Medication use and physical assaults in the psychiatric emergency room

Objective: To evaluate the relationship between medications used to treat acute agitation (antipsychotics, mood stabilizers and benzodiazepines) and subsequent assault incidence in the psychiatric emergency room. Methods: Medication orders and assault incident reports were obtained from electronic health records for 17,052 visits to an urban psychiatric emergency room from 2014-2019. Assault risk was modeled longitudinally using Poisson mixed-effect regression. Results: Assaults were reported during 0.5% of visits. Intramuscular medications (IMs) were administered in 23.3% of visits overall, and predominately administered within the first 4-hours of a visit. IM administration was correlated with assault (IRR=24.2 [5.33, 110.0]), often because IM medication was administered immediately subsequent to reported assaults. Interacted with time, IMs were not significantly associated with reduction in future assaults (IRR=0.700 [0.467, 1.04]). Neither benzodiazepines nor mood stabilizers were associated with subsequent changes to the risk of reported assault. By contrast, antipsychotic medications were associated with decreased assault risk across time (IRR=0.583 [0.360, 0.942]). Conclusions: IM order rates are high relative to overall assault incident risk. Of the three major categories of medications administered commonly in the psychiatric emergency setting, only antipsychotic medications were associated with measurable decreases in subsequent assault risk. Careful weighing of the risks and benefits of medications is encouraged; antipsychotic medication can have a significant side effect burden, and other medications (IMs, benzodiazepines, mood stabilizers) were not associated with subsequent reduction in assault risk in this analysis.